Physics
Thermodynamics
Investigating the relationship between the length of a column of air and its temperature in Celsius and by doing so find a value for Absolute Zero
Question
Investigate the relationship between the length of a column of air and its temperature in Celsius and by doing so find a value for Absolute Zero.
Variables
Independent Variable
Dependent Variable
Temperature in °C:
1. 21°C
2. 31°C
3. 41°C
4. 51°C
5. 61°C
6. 71°C
7. 81°C
Length of column in mm
Controls
Ambient Pressure – 1 Atm
Mass of air
Humidity of air – Zero humidity
Width of column – 2mm diameter
Apparatus
Capillary tube of air with Sulphuric Acid Index
Metal Ruler
Elastic Band
250ml beaker
Stirrer
Bunsen Burner
Gauze
Tripod
Method
1. Mount the tube carefully on a metal ruler and place in a 250ml beaker of water.
2. Record the initial water temperature and read off the length of the air column.
3. Heat the water until the temperature raises by 10°C and record the new length.
4. Continue until you have 7 readings.
5. Slowly replace the water with room temperature water being careful to avoid thermal shock for the glassware.
6. Repeat the readings three times.
Results
Temperature/°C
21
31
41
51
61
71
81
Length of the air column/mm
Test 1
42
45
47
50
51
54
58
Test 2
43
45
47
49
51
54
59
Test 3
43
44
46
49
51
55
60
Processed Data
Temperature/°C
Average/mm
ΔT = ± 1mm
21
43
31
45
41
47
51
49
61
51
71
54
81
59
Average = (Sum of the Values) / (Number of the test)
= (47 + 47 + 46) / 3
= (140)/3
= 47
The uncertainty of the processed data is 1°C since the biggest difference in a given set of results was 2°C (60 – 58). Hence...